Brake Problem

[redswan]

maybe somebody can help me with this...was driving along ('97 voyager) and brakes were working normally. started to notice that sometimes brake pedal would feel like it was losing pressure (spongy) and drop to the floor before slowing down. gradually started to require brake pedal almost floored before stopping and van seems to vibrate - like only one front brake and one rear brake were engaging. also, noticed a burning smell (electrical) coming from van when this would happen. van's brakes still work but now the brakes (all the time) have to be almost floored before slowing the vehicle down.

[yogi_123rd]

I think you are describing a low brake pedal condition. That is where the brake pedal is taking a longer and longer stroke before the brakes engage, and you have lost leverage force and need to pump them once to get the brakes to hold. You may also find that the emergancy brake no long holds when fully depressed.

This condition is caused by one or both of the automatic adjusters in the rear wheels not working. As the brake shoes wear, an automatic star wheel adjuster expands to keep the brake shoes as close to the drum as possible and your brake pedal high as possible. If the adjusters are not working, the brake pedal takes longer travel to engage the brakes.

If this is your problem, the rear brakes just need to be serviced. Typically, the adjusters can fail due to being rusted up and unable to turn, or the activating cable connected from the shoe to to the adjuster has rusted and broken.

[theFREAKnasty82]

that or you could have a bad master cylinder. Check also the level of your fluid; make sure it's full.

[redswan]

from reading the posts that is what i thought it could possibly be...what do you think the burning smell was though?

[theFREAKnasty82]

the only other option I can think of is that you have a caliper or wheel cylinder that's sticking and it's causing it to overheat to the point that it boils the brake fluid and causes brake fade which would lead a sinking pedal BUT, if that were the case you would have a rock hard pedal then it would start to sink. In the scenario that you are describing, it sounds more like a master cylinder. Do you know where exactly the burning smell is coming from?

[yoji6365]

Try a cheap maintenance item first, flush the old brake fluid and bleed the system. Something could be clogged, or some serious air in your lines.